Refrigerating apparatus



May 23, 1939. r R. K. MILLER ET AL i k REFRIGERATING APPARATUS Original Filed Dec. 29, 1928 2 Sheets-Sheet 2 130 i 100 I z Patented May 1939 ayton, Ohio Beflled for abandoned application Serial No.

329,156, December 29, 1928. This application January 19, 1934, Serial No. 107,394. Renewed March 17, 1937 3 Claims. (or. 230-141) This invention relates to refrigerating apparatus and more particularly to that portion of the refrigerating apparatus wherein the refrigerant and the lubricant have their pressure changed from the low pressure side to the high pressure side of the system.

An object'of this invention is to improve the emciency of refrigerant compressors of the gear type in general as used in refrigerating systems,

and also to improve in certain respects the apparatus shown in the application of Ralph K. Miller, Serial No. 316,173, filedOctober 31, 1928, now Patent No. 1,950,510, issuedMarch 13, 1934, to which reference is made, if necessary, fora more detailed description of certain unmodified parts of the apparatus.

Another object of this invention is to prevent the backward leakage of the refrigerant at the shoulders of the gears of a gear compressor of any general type.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings, wherein a preferred form of the present invention is clearly shown.

This application is a refiling' of applicants abandoned application Serial No. 329,156, filed along the line 4-4 of Fig. 2;

Fig, 5 isa top plan view. of a portion of the mechanism shown in Fig. 1 with certain parts removed; v

" Fig. 6 is a top plan view of the relatively movable plate at the ends of the gears; Fig. 7 is a bottom view of the plate shown 1 Fig. 6; r I

Fig. 2; is a top plan-view of the plate. which is placed on top of the structure shown-in Fig. 5; Fig. 9 is a vertical CIOSSPSBCfiOHfll .view of a slightly modified form of apparatus shown in Fig. 1; I l w Fig. 10 is a vertical cross-sectional view of a n further modification of the apparatus shown in Fig. 1, and

view taken Fig: 11 is a horizontal cross-sectionalview taken along the line ll-ll of Fig. 10.

Parts designated in this application with the same numerals used-in the said application of same in structure or function, are intended to perform substantially the same functions, or have substantially the same structure as such similarly numbered parts in the application of Ralph K. Miller.

In the application of Ralph K. Miller, here-.

tofore referred to, there is disclosed a refrigerat- .Ralph K, Miller, where they obviously can be the 5 ing system wherein'the refrigerant is liquefled'in a unit and the refrigerant is returned in an evaporated condition to the unit. The lubricant also is adapted to travel in a closedfcycle of which the refrigerant liquefying unit is a part.

The refrigerant liquefying unit includes a rotary gear compressor, of any suitable construction,

.and, under certain conditions, a more specific type of gear compressor having two pairs .of gears.

The gear compressor discharges the refrigerant and the lubricant into a funnel-shaped member or reservoir 14. The lubricant is maintained in this reservoir at any convenient height as indicated at 62. The refrigerant from this member or reservoir 14 passes on to a condenser, a. receiver and an evaporator and from thence it is discharged in an evaporated condition to a sealed chamber from whence it returns by suitable connections to the inlet chamber 26, for instance through the pipe 25. The compressor may be driven through the shaft by means of a motor, not shown, and the shaft 50 may in turn drive a shaft Hill which passes into the comas a whole is more specifically described in the said application of Ralph K. Miller, to which reference may be had, if necessary, for a furtherdescription. I n I The refrigerant and the lubricant'are adapted to pass from the inlet chamber 26 through an opening, not shown, in the plate 51 and through the opening 55 in the lower bearing plate 56 into the gear chamber. The opening in the plate 51 may be in alignment with the opening 55. After passing through the opening 55 the refrigerant and the lubricant are conveyed between the teeth of the gears I02 and "I3 comprising the pair of gears III to intermediate compression chambers 58 and 59. From thence the lubricant and the refrigerant are conveyed by the pair of gears II, which comprises gears ill and I05, to

a channel 69 shown dotted in Fig. 5 and which is formed vertically along the casing 21 from the passage I20 to the plate 56. The refrigerant and lubricant pass' from the channel 69 through the outlet passage I20 into the chamber I2I and from thence through the passage I22 into the funnelshaped reservoir 14, from whence the refrigerant passes to the condenser as heretofore described.

The casing 21 is provided with a cavity which, in general, hasthe same periphery as the composite periphery of the gears of the compressor. Thus the casing 21 in this particular embodiment has a cavity which follows the line I23, indicated in Fig. 5, with the exception that there are two vertical channels I and 69, which comprise, respectively, the inlet feeder and the outlet receiver of the teeth of the gears. The vertical channel I55 is in alignment with the opening 55 in the plate 56. The gears within the cavity are provided with shafts such as II2and the shaft I00. In one embodiment, these shafts have bearings I I3 in the plate 56 at the bottom, and have bearings H4 in the plate I30 at the top. -The gears also are provided with shoulders I3I at each of their ends. These shoulders I3I are adapted to be placed in two parallel planes. The lower set of shoulders are adapted to bear against the plate 56. The upper set of shoulders I3 I are adapted to have bear against them a relatively movable plate I32. The outer periphery of the plate I32 may be substantially co extensive with the composite periphery of the gears, thus following in general the line I23 shown in Fig. 5, when the gears comprise two pairs, as shown in this embodiment. The plate I32 may be resiliently movable against the gears, or it may be pneumatically movable against the gears, or it may be both resiliently and pneumatically. movable against the gears. In this particular embodiment the plate is both resiliently and pneumatically movable.

Thus springs I33 are adapted to be interposed between the plate I 32 and I30, thus resiliently moving the plate I32 against the'shoulders I3I of the gears. If desired, the springs I 33 may be placed around the shafts I00 and H2. The plate I32 may. also be pneumatically moved against the shoulders I3I. ,Thus the compressed refrigerant and lubricant passing through the passage I20.

and into the chamber I2I exert their pressure on top of the plate I32 and move it against the shoulders I3I.

If desired, a flexible hermetic seal maybe placed between the plate I32 and the casing 21 or any other stationary part which may be either an integral or a separate extensionof the casing 21. The flexible hermetic seal may comprise a metal plate I40 secured to the plate I32 and the casing I21. If desired, both the plate I32 and the casing 21 may be provided with protruding continuous ridges I H and I42 respectively. The.

flexible hermetic seal may join these ridges and, preferably, it is hermetically attached to the ridges. Thus a certain amountof relative axial movement is provided for the plate I32 without distorting or breaking the flexible hermetic seal I40. The seal may have a contour somewhat similar to the composite periphery of the gears,-

the passage I01 and thence up through an opening I6I. A convenient way of forming this passage may be by boring the passages I01, I60 and IN and by inserting a plug II 0 in order to seal the end of the passage I01. Likewise the lubricant entrapped between the intermeshing teeth of the gears I02 and I05 may be relieved at the lower end through a passage I03 formed similarlyto the last described passage I01, I60 and I6I. The upper end of these intermeshing teeth may also be provided with relief means. Thus teeth of the gears I02 and I03 may be relieved by a semi-cylindrical passage I63 formed or cut by a rotary tool inthe plate I32 and the teeth of the gears I02 and I05 may be relieved by a similar semi-cylindrical passage I64 in the plate I32.

The plate I32 may have the shafts H2 and I00 pass through it as'shown in Fig. 1, in which case the plate may be provided with openings or re-- cesses I65. However, under certain conditions, the shafts I2 need not pass through the plate I32. As shown in Fig. 9 the plate I32 may be provided with recesses I66 which extend only part of the distance through the plate. The shaft I00, however, may pass through the plate I32 as shown inFig. 9. The spring I33 may, if desired, be placed around the shaft I00, and if necessary additional springs I61 may be interposed between the plate I30 and the plate I32. These springs I61 may be positioned by any suitable means such as cylindrical lugs I68 formed in the bottom of the plate I30. In this modification there is only one passage through which the refrigerant and the lubricant may pass from the chamber I 2| back into the gear chamber. This passage is around the shaft I00. If desired, a flexible seal, not shown, may be placed between the shaft I00 and the plate I32. This seal may be of any suitable construction, for instance of, the type shown in the patent to McCuen, 1,491,992, wherein the McCuen shaft I1 corresponds to shaft I00 herein, and where McCuen plate 26 corresponds to plate I32 herein, and where the shaft I 00 herein may be axially movable .and radially keyed to its .gear I02.

In the operation of the device, the coil springs I33 resiliently at all times exert a pressure on the movable plate I32 so as to urge it at all times into contact with the shoulders or sides of the gears 10 and 1I. -The springs exert this pressure regardless of the presence of'any high pressure or compressed gas behind the movable plate I32. This force is sufiicient where moderate compression pressures are used. However, where high compression pressures occur, it is desirable to provide an additional force according to the pressure of the-compressed gas. This is done in applicants construction by conducting the discharged gas through the passage I20 to the 'opposite side of the movable plate so that the pressure of the compressed gas is exerted upon the movable plate in addition to the coil springs I33 so that an additional force is supplied to hold the movable plate tightly against the shoulders or sides of the gears. Thus, by using both the springs and the pressure of the compressed gas, a constant force provided by the springs is always available while a variable force provided by the compressed gas is available whenever compressed gas is'present and varies according to the discharge pressure. In this way, the pressure which holds the movable plate against the shoulders or sides of the gears is properly governed and regulated.

Certain features of this invention may be embodied in any type of rotary compressor. Thus in ,Figs. and 11 is shown a single pair of gears 13 1* 200 and 2M. Thesegears may be placed in'a easing 202, and a relatively movable plate 232 iymay be placed at one end of the gears and an- {periphery of the gears. In addition it may be provided with vertical inlet and outlet channels 255 and 269, similar to passages I55 and 69, refspectively, for feeding and receiving the refrig- :erant from the gears 200 and 21". The gears may be provided with shoulders 23l similar to shoulders HI and the plates 203 and 232 may have an action similar to the action of plates 56 and I32. An outlet passage 22! leads into a chamber Hi and from thence the refrigerant and utheulubricant may pass through a passage 222 .into a reservoir similar to the reservoir 14. A 3 hermetic seal 240 may be placed between the casing 202 and the plate 232. If desired this seal may be formed similar to that shown in Fig. 1, but adapted to the different type of compressor. ,Thus ridges 2H and 242 may be made in the plate 232 and the casing 202 respectively. .Springs 233 may be provided. Thus the plate 1 232 may be made either resiliently movable or pneumatically movable or both resiliently and pneumatically movable in a manner somewhat similar to the device shown in Fig. 1. The other i parts of the structure shown in Figs. 10 and 11 may be similar tothat shown in the other modiflcaticns, with such changes as may be necessary to adapt them to the different form of compressors. Thus the drive shaft 200 may pass through the plate 232, and the shaft 2I2 may pass through the plate 232 similarly to the manher in which shafts 2 pass through the plate I in Fig. 1, or the shaft 2i2 mayterminate .within the plate 232 in a manner similar, to shafts shown in Fig. 9, and shaft 200 may be provided. with a seal similar to that described .for shaft loll in F18. 9. a. ,While the form of embodiment of the invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms ,wmight be adopted, all coming within the scope -1 :1 of the claims which follow. \What is claimed is as follows: v i 01. In a refrigerating apparatus wherein lubrifcant and refrigerant are circulated in closed paths, a refrigerant compressor comprising a casing, pumping gears in said casing provided with shafts and end shoulders, plates at opposite ends of the gears having recesses receiving said shafts, one of said plates being relatively movable by pressure of the compressed refrigerant and by substantially co-extensive with the composite resilient means against at least one of said shou ders, said last named plate having a periphery substantially co-extensive with the composite periphery of said gears and fitting in a recess of substantially the same periphery formed in said casing. said movable plate incorporating pressure relief means for conducting away lubricant trapped in the intermeshing teeth of said gears.

2. A refrigerating apparatus, a portion of which includes a compressor through which the refrigerant and the lubricant are circulated in their closed cycles, said compressor including a 'casing and two pairs of gears within said casing, the gears of each pair intermeshing with each other and at least one gear of each pair intermeshing with at least one gear of the other pair, a single inlet for supplying refrigerant to one of said pairs, and a single outlet for discharging said refrigerant from the other of said pairs, said gears forming two chambers of intermediate compression between said gears and said casing, said gears being provided with shafts and end shoulders, plates at opposite ends of the gears having recesses receiving said shafts, one of said plates being relatively movable against at least one of said shoulders, said last named plate having a periphery substantially co-extensive with the composite periphery of said gears and fitting in a recess of substantially the same periphery formed in said casing, and a flexible web means hermetically secured to said last named plate and to said casing for providing a hermetic seal for said plate.

3. A refrigerating apparatus, a portion of which includes a compressor through which the refrigerant and the lubricant are circulated in their closed cycles, said compressor including a casing and two pairs of gears within said casing, the gears of each pair intermeshing with each other and at least one gear of each pair intermeshing with at least one gear of the other pair, a single inlet for supplying refrigerant to riphery formed in said casing, protruding continuous ridges formed on said last named plate and on said casing adjacent said last named recess, and a flexible web means joining said ridges for providing a hermetic seal for said plate.

RALPH K. MILLER. ROBERT R. CANDOR. 

